This invention relates to an apparatus for moving dispensing pistons and filling tubes during the filling of containers, particularly shaped bottles, and in which the movement is programmed.
During a dispensing it is necessary, depending on the filling product, to vary the speed in the intake and also in the output region. There are a series of products which are sensitive to intake and output. In this case a slower action is necessary during input at the beginning, this is then accelerated and may later be slowed down. Even in the case of pumping into a special shape of container and method used can be similar.
During the travel of the filling tube it is also important for the travel speed to keep pace with the rising filling level. Distinction is made here between an under- or an over-filling level, and certainly thus depends on the type of filling material, for example viscous or thin-flowing or foaming material. In the case of shaped bottles account has to be taken of the fact that in the waist area of a container the filling level is reached quicker and in the belly region slower. These movements are completely different from container to container.
Known are apparatus of the type in which the operation of the pistons is performed by means of eccentrics, bell crank levers or through cam plates pneumatically or hydraulically. The same control means is provided for the filling tube. During the treatment of bottles of differing shape there is a manual changeover of equipment and also an eventual exchange of parts or cam discs, skilled practitioners being required for these activities and also a large amount of time required. The pauses in operation which this involves are very unfavourable for such apparatus because they involve a loss of production.